
AIR BAG RESTRAINT SYSTEM
MAZDA 1990-91 AIR BAGS
DESCRIPTION & OPERATION
The air bag restraint system, when used in conjunction with seat belt, provides increased protection for the
driver in a collision. The air bag restraint system consists of the following: AIR BAG warning light, air bag
module, clockspring connector, diagnostic module, crash sensors, back-up battery, and wiring harnesses.
The air bag is designed to deploy when rear safing sensor and at least one front impact sensor close in a
collision, and ignition switch is in the ON position. The back-up battery supplies current for the ignitor if the
vehicle battery or fuses fail during a collision. The diagnostic module monitors the air bag system for failures. I
f
any failures are detected by the module, the driver is warned of such failure(s) through the activation or flashing
of the AIR BAG warning light.
SERVICE PRECAUTIONS
Disable air bag system before servicing any air bag system or steering column component. See
DISABLING & ACTIVATING AIR BAG
SYSTEM
Wait about 10 MINUTES after disabling air bag system before servicing. Air bag system voltage is
maintained for about 10 MINUTES after system is disabled. Failure to wait 10 MINUTES before
servicing system may cause accidental air bag deployment and possible personal injury.
On Miata, obtain radio code number from customer and deactivate radio anti-theft function before
disconnecting battery.
Because of the critical system operating requirements, DO NOT service any air bag system component.
Corrections are made by replacement only.
DO NOT use an ohmmeter to check resistance of air bag module, as it may cause air bag deployment.
When carrying a live (undeployed) module, ensure trim cover is pointed away from your body. This
minimizes chance of injure in the event ofaccidental air bag deployment.
When placing a live air bag module on any surface, always face trim cover upward to reduce motion of
module if it is accidentally deployed.
If an open circuit is present, replace entire wiring harness. DO NOT attempt wire repair.
Impact sensors must always be installed with arrow marks facing front of vehicle. Also, check sensors for
cracks, defects or rust before installation. Replace impact sensor(s) if required.
Air bag system clockspring MUST be aligned in the neutral position, since its rotation ability is limited.
DO NOT turn steerin
g wheel or column after removal of steering gear. WARNING:To avoid injury from accidental air bag deployment, read and carefully
follow all WARNINGS and SERVICE PRECAUTIONS.
NOTE: The following precautions should be observed when working with air bag
systems.
1991 Mazda MX-5 Miata
AIR BAG RESTRAINT SYSTEM MAZDA 1990-91 AIR BAGS
1991 Mazda MX-5 Miata
AIR BAG RESTRAINT SYSTEM MAZDA 1990-91 AIR BAGS
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ADJUSTMENTS
CLOCKSPRING CENTERING
Set front wheels in straight-ahead position. Turn clockspring connector clockwise until it stops (do not force).
Return connector 2 3/4 turns counterclockwise. Rotate clockspring connector further, if necessary, to align
marks on connector and outer housing.
DISPOSAL PROCEDURES
DEPLOYED AIR BAG
Dispose deployed air bag module as you would any other part. Wear gloves and safety glasses when handling
air bag module.
SCRAPPED VEHICLE
1. Ensure vehicle is outside, and away from other vehicles and people. Open convertible top and doors.
Disconnect negative battery cable.
2. Ensure air bag module is firmly mounted to steering wheel. Remove knee protector and disconnect
Orange and Blue clockspring connectors at base of steering column. See Fig. 1
. Cut clockspring
connector Blue wires.
3. Connect 2 jumper wires (20 feet long) to cut clockspring wires. Connect other ends of wires to a 12-volt
battery to deploy air bag. Because of heat, wait 10 MINUTES before touching deployed air bag.
REMOVAL & INSTALLATION
CRASH SENSORS NOTE: Perform the following procedures when scrapping a vehicle with undeployed air
bag.
WARNING:Follow air bag service precautions to prevent accidentalair bag
deployment and personal injury. See SERVICE PRECAUTIONS.
NOTE: After component replacement, check system to ensure proper operation. See
SYSTEM OPERATION CHECK.
NOTE: Crash sensor orientation and mounting is important for proper operation. All
sensors must be positioned so that arrow points forward. If there is sheet metal
damage near sensor mounting point, inspect body structure at sensor
mounting point for deformation. If damaged, restore to original shape. Ensure
sensor mounting bolts or nuts are tightened to specification. See TORQUE
SPECIFICATIONS table.
1991 Mazda MX-5 Miata
AIR BAG RESTRAINT SYSTEM MAZDA 1990-91 AIR BAGS
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Removal (Front Impact Sensors)
1. Before proceeding, follow air bag service precautions. See SERVICE PRECAUTIONS. Disable air bag
system. See DISABLING & ACTIVATING AIR BAG SYSTEM.
2. Front impact sensors are located in left front and right front of vehicle. See Fig. 2
or Fig. 3 . To remove
left or right sensor, remove wheelwell undercover, and disconnect connector(s). Remove retaining clips
and bolts. Remove sensor(s).
Fig. 2: Locating Crash Sensors (Miata)
Courtesy of MAZDA MOTORS CORP.
1991 Mazda MX-5 Miata
AIR BAG RESTRAINT SYSTEM MAZDA 1990-91 AIR BAGS
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ACTIVATING AIR BAG SYSTEM. Check AIR BAG indicator light to ensure system is functioning properly.
See SYSTEM OPERATION CHECK.
AIR BAG MODULE
Removal & Installation
1. Before proceeding, follow air bag service precautions. See SERVICE PRECAUTIONS. Disable air bag
system. See DISABLING & ACTIVATING AIR BAG SYSTEM.
2. Air bag module is located on center of steering wheel. See Fig. 4
or Fig. 5 . Remove air bag module nuts
and remove module from steering wheel. To install, reverse removal procedure. Tighten air bag module
mounting nuts to specification. See TORQUE SPECIFICATIONS table. Reactivate air bag system. See
DISABLING & ACTIVATING AIR BAG SYSTEM. Check AIR BAG indicator light to ensure system is
functioning properly. See SYSTEM OPERATION CHECK.
Fig. 4: Identifying Air Bag System Components (Miata)
Courtesy of MAZDA MOTORS CORP.
1991 Mazda MX-5 Miata
AIR BAG RESTRAINT SYSTEM MAZDA 1990-91 AIR BAGS
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Fig. 5: Identifying Air Bag System Components (RX7 Convertible)
Courtesy of MAZDA MOTORS CORP.
STEERING WHEEL
Removal & Installation
Remove air bag module. See AIR BAG MODULE. Remove steering wheel nut. DO NOT strike steering shaft
with a hammer, or steering shaft may collapse. Remove steering wheel with steering wheel puller. To install,
reverse removal procedure. Tighten steering wheel nut to specification. See TORQUE SPECIFICATIONS
table.
CLOCKSPRING CONNECTOR ASSEMBLY
Installation
1. To install, reverse removal procedure. Before installing steering wheel, center clockspring. See
CLOCKSPRING CENTERING under ADJUSTMENTS. Tighten steering wheel nut to specification. See
TORQUE SPECIFICATIONS table.
2. After installing clockspring connector and combination switch assembly, reactivate air bag system. See
DISABLING & ACTIVATING AIR BAG SYSTEM. Check AIR BAG indicator light to ensure system is
functionin
g properly. See SYSTEM OPERATION CHECK.
NOTE: Clockspring connector assembly is part of the combination switch. When
replacing clockspring, replace clockspring and combination switch as an
assembly.
1991 Mazda MX-5 Miata
AIR BAG RESTRAINT SYSTEM MAZDA 1990-91 AIR BAGS
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Removal
1. Before proceeding, follow air bag service precautions. See SERVICE PRECAUTIONS. Disable air bag
system. See DISABLING & ACTIVATING AIR BAG SYSTEM.
2. Clockspring connector assembly is located under steering wheel, in steering column. See Fig. 4
or Fig. 5.
Remove air bag module. See AIR BAG MODULE. Remove steering wheel nut and remove steering
wheel with steering wheel puller. Remove column covers. Remove screws. Remove clockspring
connector and combination switch as an assembly.
DIAGNOSTIC MODULE & BACK-UP BATTERY
Removal & Installation
1. Before proceeding, follow air bag service precautions. See SERVICE PRECAUTIONS. Disable air bag
system. See DISABLING & ACTIVATING AIR BAG SYSTEM.
2. Diagnostic module and back-up battery is located under left side of instrument panel. See Fig. 4
or Fig.
5 . Disconnect diagnostic module and back-up battery connectors. Remove nuts. Remove diagnostic
module and back-up battery as an assembly. To install, reverse removal procedure. After diagnostic
module and back-up battery are installed, reactivate air bag system. See DISABLING & ACTIVATING
AIR BAG SYSTEM. Check AIR BAG indicator light to ensure system is functioning properly. See
SYSTEM OPERATION CHECK.
SYSTEM OPERATION CHECK
Turn ignition switch to the ON or START position. AIR BAG warning light in instrument cluster should
illuminate for approximately 6 seconds then go out. This indicates that the air bag system is functioning
properly. If any of the following conditions exists, air bag system is malfunctioning and needs repair.
AIR BAG warning light does not illuminate as described.
AIR BAG warning light stays on for more than 6 seconds.
AIR BAG warning light illuminates while driving.
If air bag system components are replaced for any reason, air bag system must be checked for proper function
after repair. Turn ignition on. AIR BAG warning light should illuminate for approximately 6 seconds then go
out. If AIR BAG warning light does not illuminate as described, air bag system is malfunctioning and needs
repair. If warning light functions as described, check horn operation. If horn does not sound, remove air bag
module and check air bag module and horn switch connections. Always follow service precautions and
deactivate air bag system before performing repairs. See DISABLING & ACTIVATING AIR BAG
SYSTEM .
WIRE REPAIR
DO NOT repair air bag system wiring. If air bag harness connectors are faulty, replace faulty wiring harness.
TORQUE SPECIFICATIONS
1991 Mazda MX-5 Miata
AIR BAG RESTRAINT SYSTEM MAZDA 1990-91 AIR BAGS
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WHEEL SPEED SENSOR ROTORS
Inspection
Perform a comprehensive visual inspection of sensor rotor. If any damage is noted, replace sensor rotor. Sensor
rotors are attached to wheel hubs.
REMOVAL & INSTALLATION
HYDRAULIC UNIT
Removal
Remove hydraulic lines from unit. Disconnect hydraulic unit connectors. Remove nuts securing unit. Remove
hydraulic unit.
Bleeding Hydraulic Unit
Before bleeding hydraulic unit, bleed brake system in appropriate sequence. See BRAKE LINE BLEEDING
SEQUENCE TABLE under BLEEDING BRAKE SYSTEM. Bleed hydraulic unit by opening bleeder screw on
unit. See Fig. 12
.
Installation
To install, reverse removal procedure. Tighten mounting bolts to specification. See TORQUE
ApplicationConnector Terminals (1)
Miata
Left Front"K" & "G"
Left Rear"O" & "Q"
Right Front"U" & "F"
Right Rear"L" & "P"
RX7
Left Front"D" & "F"
Left Rear"H" & "I"
Right Front"U" & "W"
Right Rear"X" & "Z"
929
Left Front"K" & "G"
Left Rear"O" & "Q"
Right Front"J" & "F"
Right Rear"L" & "P"
(1)See Fig. 4 or Fig. 5 to identify ABS control unit terminals.
1991 Mazda MX-5 Miata
ANTI-LOCK BRAKE SYSTEM 1988-91 BRAKES Mazda Anti-Lock Brake System
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SPECIFICATIONS TABLE at end of article.
Fig. 12: Locating Hydraulic Unit Bleeder Screw
Courtesy of MAZDA MOTORS CORP.
WHEEL SPEED SENSOR ROTOR
Removal (Miata)
Remove brake caliper. Remove wheel hub. On rear axle, carefully remove sensor rotor from axle using a chisel.
On front rotor, remove sensor rotor using Puller (49- 0839-425C).
Installation
Press sensor rotor onto axle using Installer (49- H026-101A). Install sensor rotor on front rotor with chamfered
edge toward hub using Press Adapter (49-F001-95). To complete installation, reverse removal procedure.
Tighten mounting bolts to specification. See TORQUE SPECIFICATIONS TABLE at end of article.
Removal & Installation (RX7)
Remove brake caliper and wheel hub. On rear hub, remove wheel hub from outer toe control hub using Puller
(49-F026-103) and Installer (49-F026-102). On front rotor, remove rotor-to-hub bolts using Allen wrench. On
rear rotor, remove rotor-to-hub screws. To install, reverse removal procedure. Tighten mounting bolts to
specification. See TORQUE SPECIFICATIONS TABLE at end of article.
Removal & Installation (929)
1991 Mazda MX-5 Miata
ANTI-LOCK BRAKE SYSTEM 1988-91 BRAKES Mazda Anti-Lock Brake System
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